[llvm/DebugInfo] Emit DW_OP_implicit_value when tuning for LLDB

This patch enables emitting DWARF `DW_OP_implicit_value` opcode when
tuning debug information for LLDB (`-debugger-tune=lldb`).

This will also propagate to Darwin platforms, since they use LLDB tuning
as a default.

rdar://67406059

Differential Revision: https://reviews.llvm.org/D90001

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -2513,7 +2513,8 @@ void DwarfDebug::emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
     // encoding is supported.
     DwarfExpr.addWasmLocation(Loc.Index, static_cast<uint64_t>(Loc.Offset));
   } else if (Value.isConstantFP()) {
-    if (AP.getDwarfVersion() >= 4 && AP.getDwarfDebug()->tuneForGDB()) {
+    if (AP.getDwarfVersion() >= 4 && (AP.getDwarfDebug()->tuneForGDB() ||
+                                      AP.getDwarfDebug()->tuneForLLDB())) {
       DwarfExpr.addConstantFP(Value.getConstantFP()->getValueAPF(), AP);
       return;
     } else if (Value.getConstantFP()

llvm/test/DebugInfo/X86/implicit_value-double.ll

@@ -1,14 +1,23 @@
 ;; This test checks for emission of DW_OP_implicit_value operation
 ;; for double type.
 
-; RUN: llc -debugger-tune=gdb -filetype=obj %s -o - | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -debugger-tune=gdb -filetype=obj %s -o -  | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -debugger-tune=lldb -filetype=obj %s -o - | llvm-dwarfdump - | FileCheck %s
 
 ; CHECK: .debug_info contents:
 ; CHECK: DW_TAG_variable
 ; CHECK-NEXT:  DW_AT_location        ({{.*}}
 ; CHECK-NEXT:                     [{{.*}}): DW_OP_implicit_value 0x8 0x1f 0x85 0xeb 0x51 0xb8 0x1e 0x09 0x40)
 ; CHECK-NEXT:  DW_AT_name    ("d")
 
+; RUN: llc -debugger-tune=sce -filetype=obj %s -o -  | llvm-dwarfdump - | FileCheck %s -check-prefix=SCE-CHECK
+
+; SCE-CHECK: .debug_info contents:
+; SCE-CHECK: DW_TAG_variable
+; SCE-CHECK-NEXT:  DW_AT_location        ({{.*}}
+; SCE-CHECK-NEXT:                     [{{.*}}): DW_OP_constu 0x40091eb851eb851f, DW_OP_stack_value)
+; SCE-CHECK-NEXT:  DW_AT_name    ("d")
+
 ;; Generated from: clang -ggdb -O1
 ;;int main() {
 ;;        double d = 3.14;

llvm/test/DebugInfo/X86/implicit_value-float.ll

@@ -1,14 +1,23 @@
 ;; This test checks for emission of DW_OP_implicit_value operation
 ;; for float type.
 
-; RUN: llc -debugger-tune=gdb -filetype=obj %s -o - | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -debugger-tune=gdb -filetype=obj %s -o -  | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -debugger-tune=lldb -filetype=obj %s -o - | llvm-dwarfdump - | FileCheck %s
 
 ; CHECK: .debug_info contents:
 ; CHECK: DW_TAG_variable
 ; CHECK-NEXT:  DW_AT_location        ({{.*}}
 ; CHECK-NEXT:                     [{{.*}}): DW_OP_implicit_value 0x4 0xc3 0xf5 0x48 0x40)
 ; CHECK-NEXT:  DW_AT_name    ("f")
 
+; RUN: llc -debugger-tune=sce -filetype=obj %s -o -  | llvm-dwarfdump - | FileCheck %s -check-prefix=SCE-CHECK
+
+; SCE-CHECK: .debug_info contents:
+; SCE-CHECK: DW_TAG_variable
+; SCE-CHECK-NEXT:  DW_AT_location        ({{.*}}
+; SCE-CHECK-NEXT:                     [{{.*}}): DW_OP_constu 0x4048f5c3, DW_OP_stack_value)
+; SCE-CHECK-NEXT:  DW_AT_name    ("f")
+
 ;; Generated from: clang -ggdb -O1
 ;;int main() {
 ;;        float f = 3.14f;

llvm/test/DebugInfo/X86/stack-value-piece.ll

@@ -26,15 +26,15 @@
 ; CHECK:   DW_AT_name ("f")
 ; CHECK:   DW_TAG_variable
 ; CHECK-NEXT:   DW_AT_location ([[F:0x[0-9a-f]+]]
-; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
-; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4)
+; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, {{(DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4|DW_OP_implicit_value 0x4 0x00 0x00 0x00 0x00)}}
+; CHECK-NEXT:     [{{.*}}, {{.*}}): DW_OP_piece 0x4, {{(DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4|DW_OP_implicit_value 0x4 0x00 0x00 0x00 0x00)}})
 ; CHECK-NEXT:   DW_AT_name ("r")
 ;
 ; CHECK: .debug_loc contents:
 ; CHECK:      [[I]]:
 ; CHECK-NEXT:   ({{.*}}, {{.*}}): DW_OP_reg5 RDI, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
 ; CHECK:      [[F]]:
-; CHECK-NEXT:   ({{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
+; CHECK-NEXT:   ({{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, {{DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4|DW_OP_implicit_value 0x4 0x00 0x00 0x00 0x00}}
 
 source_filename = "stack-value-piece.c"
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"